Article seating device



Aug. 28, 1962 H. J. BLOOM ARTICLE SEATING DEVICE 2 Sheets-Sheet l Filed Nov. .3, 1958 m a R 0 Y E m5 N m m wf 4w 0 W m? Aug. 28, 1962 H. J. BLOOM ARTICLE SEATING DEVICE 2 Sheets-Sheet 2 Filed Nov. 5, 1958 0 R/ m V ATTORNEY United States Patent Ofifice 3,051,329 Patented Aug. 28, 1962 3,051,329 ARTICLE SEATING DEVICE Herbert J. Bloom, Brookville, Pa., assignor, by mesne assignments, to Sylvania Electric Products Inc., Wilmmgton, Del., a corporation of Delaware Filed Nov. 3, 1958, Ser. No. 771,595 3 Claims. (Cl. 214-1) This invention relates in general to article positioning devices and more particularly to mount seating devices for use with an envelope sealing machine in the production of electron discharge devices.

In the production of electron discharge devices such as radio receiving tubes it is necessary to enclose the electrode assembly in an envelope at some time during the manufacturing process. Generally, this involves sealing together a glass envelope and a header or glass wafer through which the lead wires pass and upon which is mounted the electrode assembly. The composite header and electrode assembly will hereafter be referred to as a mount. The envelope which is to be sealed to the mount has an inside diameter slightly larger than the outside diameter of the header. During the sealing operation the glass of the envelope is caused to flow and close the gap.

Prior to this invention, the mount was positioned manually upon a sealing post or article retainer which is mounted on the periphery of an indeXible turret in the machine used in sealing the envelope to the mount. The envelope is then automatically placed over the mount at one position of the turret. The location of the bottom or open end of the envelope relative to the top of the sealing post is automatically controlled by the envelope loading device. To produce a proper wafer to envelope seal a predetermined amount of overlap of the envelope over the header must be achieved. Since the vertical position of the envelope relative to the sealing post is constant, variation in the vertical position of the wafer relative to the sealing post resulted in an increase in the amount of glass in the seal subsequently formed. In the event that an excess amount of glass was present in the seal an increased tendency for the formation of cracks in the seal on the header resulted in an increased number of rejected tubes.

Therefore, it is an object of this invention to seat the mount portion of an electron discharge device on a sealing post during manufacture with a minimum variation in given position.

It is a further object of this invention to seat a mount at a high rate of speed with complete safety for the apparatus in the event of jamming.

The foregoing objects are achieved in one embodiment of the invention by the provision of article seating means mounted adjacent :a workstation for seating in a given position a plurality of articles delivered in sequence to the workstation. The article seating means is mounted for compound movement relative to the given position and is provided with fluid motor means for moving the article seating means into contact with the article to be seated and for seating the article at said given position. The article seating means is mounted on a yieldable support means which allows the article seating head to be moved from its operative position to an inoperative position whereby the head is removed from contact with the article seated.

For a better understanding of the invention, reference is made to the following' description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevation view in partial section show ing the construction of the article seating rrieans and associated fluid motor and support means,

FIG. 2 is a view similar to FIG. 1 showing the article seating means in the article seating position and a fragment of the associated sealing machine,

FIG. 3 is a perspective view showing the relation of the parts of FIG. 1 and FIG. 2, and

FIG. 4 is also a perspective view of the opposite side of the device showing the adjustable stop mechanism.

Referring to the drawings, a mount seating device 10 is provided for seating a completed mount 12 which has previously been placed on a sealing post 14 of an envelope to wafer sealing machine 16. The vertical position of the mount varies from mount to mount due to the manner in which they are manually inserted on the post by an operator. The sealing posts 14 are mounted on the periphery of an indexibt'le turret 18. The mount seating device has article seating means 20 formed for movement relative to the sealing post position. The movement of the article seating means 20 is produced by the fluid motor means 24. The mount seating device 10 is carried by a shiftable or yieldable support 22 so that it may be moved, in an arcuate path, clear of the sealing peg 14 to a disengaged position when the turret 18 indexes to bring a subsequent sealing post and associated mount to the workstation without damaging the sealing post if the article seating means 20 is jammed in its advanced or seating position.

Referring to FIGS. 1 and 2, the fluid motor 24 consists in part of a main cylinder 26 and an end cap 28. The main cylinder has a central bore 30 and a passage 32 which connects the central bore to a port 34. A fluid conduit 36 terminates in the port. The end cap 28 has a bore 38 which connects with the central bore 30 of the main cylinder 26. The bores 30, 38 of the main cylinder 26 and end cap 28 are axially aligned. The end cap 28 has a port 40 and passage 42 which connects with the central bore 30 when the parts are assembled. A fluid conduit 44 terminates in the port 40. An arm 46 of the end cap 28 extends outwardly from the cap parallel to the axis of bore 38. A stop 48 is formed at the end of the arm 46.

A piston 50 is slidably mounted within the main bore 30 of the cylinder 26. An 0 ring 52 is provided for making an air tight seal between the piston and the main bore 30. The ram member 54 which passes through the bore 38 of the end cap 28 is attached to the piston 50. A second 0 ring 56 is provided on the ram 54 to provide a seal between the ramand the bore 38 of the end cap 28. A U shaped member 58, hereafter called the yoke, is carried, with the legs 60 of the U upright, by the ram 54 which passes through it. The yoke 58 is held to the ram 54 by the coaction of a shoulder 62 on the ram with a nut 64 on the threaded portion 66 of the ram. A horizontal pivot pin 68 extends between the upright legs 60 of the yoke 58. Pivoted on the horizontal pin 68 is a fork-like member 70 having a bait 72 and two prongs 74. The fork-like member 70 is also provided with two stop members 76, 78. The first or lower stop 76 cooperates with the fixed stop 48 to produce the rotation of the fork-like member 70 about the pivot pin 68. The second or upper stop 78 coacts with a horizontal member 80 which spans the upright legs 60 of the yoke, and is held by bolts 82 thereto, to limit the travel and inclination of the fork-like member 70. Biasing spring 84 is provided between the horizontal member 80 and the haft portion '72 of the fork-like member 70. The horizontal member 80 has an inclined surface 86 which cooperates with the upper stop 78 when the spring 84 is able to bias the fork-like member 70 to an inclined position.

The main cylinder 26 of the fluid motor means 24 is attached by bolts 88 through the shoulder 90 of the vertical pivot shaft 92 of the yieldable support means (see FIG. 1). The shaft 92 is held in a housing 94 by the cooperation of the shoulder 90 and a C ring 96 at- 3 tached to the shaft 92 below the housing 94. A washer 98 is positioned between the O ring 96 and the pivot housing 94 to provide a bearing surface. A collar 100 is positioned at the end of the pivot shaft 92 remote from the fluid motor means 24 for cooperation with torsion spring 102 which is connected between the collar 100 and the pivot housing 94 about the shaft 92, thus providing a yieldable support. An adjustable stop support member 104 (see FIG. 4) is fastened by screws 106 to the pivot housing 94 and has connected to it an adjustable threaded stop 108 which limits the arcuate travel of the mount seating device 10.

The pivot shaft housing 94 is adjustably attached by bolts 110 to a support bracket 112 which is in turn mounted by bolts 114 to a support (not shown) on the sealing machine 16.

Referring to FIG. 2, a fragment of the turret 18 of sealing machine 16 is shown. Mounted on the turret is a sealing post 14 having a pin receiving slot 116 in which the lead-in pins 118 depending from the wafer 120 of the mount 12 are held during the sealing process. An electrode cage 122 is shown connected to what will be the internal ends of the lead-in pins 118 in the completed tube. Referring to FIGS. 1 and 2, a mount 12 is manually placed on a sealing post 14 of the sealing machine 16 at a position prior to the seating operation which will be described in detail. The lead-in pins 118 of the mount 12 fit securely in the groove or slot 116 in the sealing post 14 with a result that some of the wafers 120 do not contact the top of the sealing post 14 which is the desired position as previously explained. The article positioning device hereinbefore described is provided to assure the seating of the mount 12 on the sealing post 14 to this position. Indexing operation of the turret 18 of the sealing machine 16 brings the sealing post 14 on which the mount 12 is to be positioned opposite the retracted positioning means 20 of the subject device. The mount positioning device is mounted so that the longitudinal axis of the ram 54 is radially aligned with the turret 18. The mount 12 is at a position, due to the adjustment of the indexing mechanism of the sealing machine, wherein the prongs 74 of the seating member 70 will safely embrace the mount 12 when the positioning device is operated.

The cycle of operation starts with the ram in its retracted position (FIG. 1) and with the article seating means 20 clear of the path of the mount 12 and sealing post 14 when the turret 18 indexes. A 4-way solenoid valve (not shown) controlled by a timing cam (not shown) on the sealing machine allows the application of fluid pressure through the conduit 26, port 34 and passageway 32 into the main bore 30 of the cylinder 26 causing the piston 50 and ram 54 to advance. The yoke 58 which is mounted on the ram is advanced carrying with it the fork-like article seating member 70. At this time the fork-like member 70 is biased to an inclined position by the action of the biasing spring 84. Its movement is limited by the coaction of the stop 78 on the fork-like member 70 and the inclined edge 86 of the bar 80. As the yoke 58 continues to advance the prongs 74 of the fork-like member 70 pass on either side of the mount 12 between the bottom of the electrode cage 122 and the wafer 120. Continued advance of the yoke 58 brings the stop '76 on the fork-like member 70 in contact with the fixed stop 48 on the arm 46 of the end cap 28. Thereafter the continued advance of the yoke 58, while the stops 76, 48 are in contact, causes the fork-like member 70 to pivot about the horizontal pivot pin 68. This pivoting action causes the fork-like member to move from its inclined position to a horizontal position. The fork-like article seating member 70 continues to move forward while rotating which motion may be described as a compound movement relative to the given position which is the upper surface of the sealing post 14. The distance between the prongs 74 is smaller than the diameter of the wafer 120. Thus as the fork-like member 70 rotates about its pivot 68, prongs 74 contact the wafer 120 and cause it to move downwardly until the wafer 120 contacts the top of the sealing peg 14. The height of the contacting surface of the prongs 74 above the upper surface of the sealing post 14 at the conclusion of the advance of the yoke 58 is dependent upon the adjustment of the position of the pivot housing 94 relative to the sealing machine 16. Since this is constant once adjusted, the given position to which the wafer is moved will be the same for all seating operations. Operation of the 4-way solenoid valve (not shown) by the timing cam (not shown) on the sealing machine 16 releases the fluid pressure applied through port 34 and causes the application of fluid pressure through conduit 44, port 40, passage 42 and then to the main bore 30 of the cylinder 26 causing the piston 50 to withdraw, thus withdrawing the ram 54 and the yoke 58.

In the event that the ram 54 for some reason should fail to withdraw from the extended position prior to the next index of the turret 18 the article positioning device is provided with a yieldable support means 22. This yieldable support allows the article positioning means to pivot or move in an arcuate path about the vertical axis of the shaft 92 from an operative position to an inoperative position so that the turret 18 of the sealing machine 16 may continue to index without the destruction of the mount or sealing post due to the interference of the parts. Torsion spring 102 which reacts between the collar and the pivot housing 94 provides sufficient force to return the article seating means to its original position when the device is deflected. The rest position of the article positioning device relative to the mount 12 may be angularly controlled in part by the adjustable stop 108 (FIG. 4) which adjusts the position of the article positioning means relative to the pivot housing.

Although several embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appended claims.

What is claimed is:

1. An apparatus for seating in a given position a plurality of articles delivered in sequence to a workstation comprising; article seating means having a U-shaped yoke member with upstanding legs, a pivot pin between said legs, a fork-like seating member mounted on said pin, said fork-like member having a first stop and a second stop formed thereon, a bar member spanning and attached to the free ends of said yoke legs, biasing means between the forkalike member and the bar member to bias the fork-like seating member to a non-engaging position wherein said first stop contacts said bar member, said fork-like article seatin g member being mounted adjacent the workstation for compound movement relative to said given position, means formed to move said article seating means and means to engage said second stop on the fork-like seating member to overcome said bias when said article seating means is moved whereby the fork-like seating member is moved into engagement with said article to provide seating thereof at said given position.

2. In an apparatus for seating in a given position a plurality of articles delivered in sequence to a workstation, each of said articles having a mid-portion of a given size and opposite end portions larger than said given size, the combination comprising article seating means having a U-shaped yoke member with upstanding legs, a pivot pin between said legs, a fork-like seating member mounted on said pin, said fork-like member having a first stop and a second stop formed thereon, said fork-like member comprising two prongs attached to a common base member, said prongs being spaced apart a distance slightly larger than said mid-portion of said article, a bar member spanning and attached to the free ends of said yoke legs, biasing means between the forklike member and the bar member to bias the fork-like member to a non-engaging position wherein said first stop contacts said bar member, said fork-like article seating member being mounted adjacent the workstation for compound movement relative to said given position, means formed to move said article seating means, and means to engage said second stop on the fork-like seating member to overcome said bias when said article seating means is moved whereby the fork-like seating member is moved between the end portions of said article adjacent said mid-portion and then engages said article to provide seating thereof at said given position.

3. In combination with a processing machine including a support movable in a given direction and article receiving means fixed on the support movable to a Workstation, of an apparatus at said workstation for seating, in a given position, articles delivered to the article receiving means, said apparatus comprising a shiftable support mounted in a housing, spring means between said shiftable support and said housing biasing said shiftable support to a given position and said shiftable support being movable from said biased position by an article which is moved away from said Workstation and is in driving engagement with said shiftable support, article seating means mounted on said support means having a fork-like seating member for engaging the article at the workstation, said article seating member being formed with a stop, said seating means being provided with biasing means for releasably maintaining said seating member in a rotatably inclined non-engaging position relative to said given position, said fork-like member being mounted adjacent the workstation for reciprocating compound lateral and rotational movement relative to said given position, means for laterally moving said fork-like member, and means formed to engage the stop on said fork-like member during lateral movement toward said given position and overcome said biasing means to rotationally pivot said fork-like member into engagement with said article to provide seating thereof in said given position at the workstation.

References Cited in the file of this patent UNITED STATES PATENTS 409,008 Breymann Aug. 13, 1889 2,419,484 Danziger Apr. 22, 1947 2,677,342 Miller May 4, 1954 2,764,806 Woodard Oct. 2, 1956 2,868,240 Roeber Ian. 13, 1959 2,944,499 Schaufelberger July 12, 1960 

